Abstract:  With the implementation of the Kigali Amendment, the currently widely used hydrofluoropropane gas fire extinguishing agent represented by heptafluoropropane, as a typical non-carbon dioxide greenhouse gas, will be restricted and phased out, and it is of great significance to find alternative new chemical gas fire extinguishing agents. The environmentally friendly HFO-1234ze(E) has been widely used as a new refrigerant, and it is also within the screening range of alternative fire extinguishing agents as a fluoroolefin. In this paper, the extinguishing concentration of HFO-1234ze(E) was determined by cup burner. At the same time, the influence of air flow on its fire extinguishing concentration was studied, and its possible fire extinguishing mechanism was analyzed. The experimental results show that the critical extinguishing volume fraction of HFO-1234ze(E) on heptane flame is 11.5%, which has a strong inhibitory effect on the flame and is not greatly affected by the air flow. Its possible main fire extinguishing mechanism is to use the fluorine-containing group produced by its high-temperature decomposition to capture the free radicals of the combustion reaction and terminate the chain reaction to extinguish the flame. Therefore, HFO-1234ze(E) can be further studied as an environmentally friendly alternative fire extinguishing agent.

Key words: HFO-1234ze（E）, cup burner, alternative fire extinguishing agents, critical extinguishing volume fraction, fire extinguishing mechanism